Automatic train-stop.



E. C. STAFFORD.

AUTOMATIC TRAIN STOP. APPLICATION FILED MAY 1. 19|5. RENEWED MAY 5.1917.

Patented Dec. 11,1917.

2 SHEETS--SHEET lvwemor E. C. STAFFORD.

AUTOMATIC TRAIN $TOP..

APPLICATION FILED MAY 1. I9l5. RENEWED MAY 5.1917.

Imam V501 jford,

Mimi/tu SHEETSSHEET 2.

Patented Dec. 11, 1917.

2 FIG 1% ,Earl 01 5m through its supporting connection. A spring 44, cooperates with the supporting arm for the shoe 40, and normally holds the same raised. At the lower end of the arm 32, is a plate 33, which is insulated from, but rigidly attached to the arm 32, by suitable bolts 84.

\Vhen the shoe 40, is in the position shown in Fig. I, of the drawings, the rocker arm 30, is released, and the valve rod 7, is free to move up and down, except for the controlling latch 25. If this latch 25, is ineffective,

then the air will open the valve and permit the application of the brakes, while on the other hand, if the latch is effective, then the release of the rocker arm 30, merely shifts the control of the automatic train stop to the latch 25. If the shoe 40, is raised through the action of the spring 44, an upwardly projecting arm 45, carried by the shoe 40, will engage'the plate 33, and will prevent the arm 30, from swinging, and the shoe 40, thus becomes efiective to hold the valve 5, closed, to prevent the application of the brakes. In other words, when the shoe 40, is out of contact with the third rail 48, it is eti'eetive at all times to prevent the application of the brakes by the action of the valve. While when the shoe is in contact with the third rail, it is drawn downward, so as to mechanically release all control of the valve.

Formed integrally with latch 25, is an arm 27, which extends outwardly from the bracket and carries an armature 28, held in operative relation to the electro-magnet 29. lVhen the magnet is energized, the armature is held against it, and the latch occupies the position shown in Fig. I, thereby locking the valve and preventing the application of the brakes. When, however, the magnet is de'e'nergfized, the arm 27, is no longer held against it, but is free to turn on its pivot 24, thereby releasing the latch 25, and the spring 19. In this way the electrical control is provided. But since, as has been pointed out, the shoe 40, serves to lock the valve when in the raised position, the electrical control becomes effective only when the shoe is lowered and the mechanical control released.

Located in the pipe 2, is a valve 50, which is controlled by an arm 51, which may be sealed in any well known way. If the train stop becomes ineffective for any reason, the seal of the valve may be broken, and the train stop entirely cut out, which will enable the engineer to proceed, but which will also indicate to an engine inspector, that for some reason the train stop has become deranged and requires attention as to repairs.

In operation, the shoe 40, is normally held in the raised position under the action of the spring 44, so that the valve is kept closed. In this position it is immaterial whether rail, it is possible, by properly connecting the energizing coil of magnet 29, with the shoe 40, to energize the magnet whenever the third rail is energized. By connecting the third rail so that it is only energized when the signals are set for satety, it is possible to automatically stop all trains which attempt to pass a signal station not set for safety.

Having thus described my invention, I claim:

1. In an automatic train stop the combination of a valve chamber. a valve reciproeating therein, mechanical mean normally tending to keep said valve seated, a spring adapted when placed under tension to keep said valve seated, and electrical means adapted to act independently of said mechanical means for controlling the tension of the spring.

2. In an automatic train stop, the combination of a valve chamber. a valve reciprocating therein. a valve rod connected with said valve extending beyond said valve chamber, a slot near the end of said valve rod, a rocker arm engaging said slot, and adapted in one position to hold said valve seated, and mechanical means for holding said rocker arm in this position.

3. An automatic train stop, including a valve chamber. a valve therein, a spring for normally holding said valve seated. a second spring cooperating with said first named spring, adapted when placed under tension to prevent the opening of the valve by the air pressure, and devices for controlling the compression of said second named spring.

4. An automatic train stop, including a valve chamber, a valve therein, a spring for normally holding said valve seated. a second spring cooperating with said first named spring, adapted when placed under tension to prevent the opening of the valve by the air pressure, and devices for controlling the compression of said second named spring said valve chamber having an opening leading therefrom and an apertured plug for closing said opening.

5. An automatic train stop, including a valve chamber, a valve therein, a valve rod, connected to said valve, a collar attached to said valve rod, a spring in the valve chamber, normally tending to hold the valve seated, said valve chamber having an outlet opening, an apertured pine for closing said outlet opening-,a spring surrounding the iltl llti

valve rod, outside of said chamber, and engaging the collar, and an adjustable sleeve forming an abutment for the other end of said spring, and means for holding said sleeve for placing the last named spring under compression.

6. An automatic train stop, including a valve chamber, a Valve therein, a valve rod, connected to said valve, a collar attached to said valve rod, a spring in the valve chamber, normally tending to hold the valve seated, said valve chamber having an outlet opening, an apertured plug for closing said outlet opening, a spring surrounding the valve rod, outside of said chamber, and engaging the collar, an adjustable sleeve fornr ing an abutment for the other end of said spring, means for holding said sleeve for placing the last named spring under compression, a rocker arm pivoted to the lower end of said valve rod, and devices cooperating with said rocker arm for holding said valve seated.

'7. An automatic train stop, including a valve chamber, a valve therein, a valve rod connected to said valve, a collar attached to said valve rod, a spring in the valve chamber, normally tending to hold the valve seated, said valve chamber having an outlet opening, an apertured plug for closing said outlet opening, a spring surrounding the valve rod, outside oi said chamber, and engaging the collar, an adjustable sleeve forming an abutment for the other end of said spring, means for holding said sleeve for placing the last named spring under compression, a rocker arm pivoted to the lower end of said valve rod, devices cooperating with said rocker arm for holding said valve seated, and an adjustable screw for limiting the movement of the valve rod when said valve is unseated.

In testimony whereof, I have hereunto signed my name, at Philadelphia, Pennsylvania, this thirtieth day of April, 1915.

EARL G. STAFFORD. Witnesses James H. BELL, E. L. FULLERTON.

denies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

